This article was originally published in the May/June 1998 issue of Home Energy Magazine. Some formatting inconsistencies may be evident in older archive content.

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Home Energy Magazine Online May/June 1998

TRENDS

Town Awash in H-Axis Machines

Bern residents were far more satisfied with the washing performance of the h-axis machines than they were with their old units.

Horizontal-axis washers like this one proved their worth at saving water and energy.

Last year, scientists from Oak Ridge National Laboratory (ORNL) conducted a unique field evaluation of high-efficiency horizontal-axis (h-axis) washers. They replaced every washing machine in the Kansas town of Bern (population 200) and collected data on every load of laundry the residents washed for two months. From the collected data, they found out what high-efficiency washers did to individuals' energy and water consumption, laundry habits, and perceptions. To learn how the new washers affected Bern's water supply and wastewater generation, they organized two days of heavy washing--one before the retrofit, and one after.

The ORNL scientists, John Tomlinson and Tom Rizy, were working through the DOE's Energy Star Program with cooperation from Maytag Appliances. They wanted to evaluate and show the benefits of high-efficiency washers and accelerate market acceptance of these devices.

During the first phase of the study, Tomlinson and Rizy monitored 103 clothes washers in the town and the surrounding rural water district. They collected data in a variety of ways. They metered washers for hot- and cold-water consumption, issued standard detergent cups to help participants measure detergent accurately, measured faucet water temperatures in each home before each phase of the study, and estimated washer energy consumption based on information provided by manufacturers. Residents weighed their laundry before and after washing and filled out questionnaires about each load, describing whether they used any pretreatments, how soiled the laundry was, what wash and rinse settings they used, and how satisfied they were with the cleanliness and dampness of the washed clothes.

After two months of data collection, Maytag Appliances replaced all of the washers with new h-axis units (see Revolution Not Agitation: A New Spin on Clothes Washing, HE Nov/Dec '96, p. 7). The scientists continued to collect data for three more months. Overall, they collected detailed data on more than 20,000 loads--nearly 70 tons--of wash from a wide range of real-world conditions.

In every home, the new washer used less total energy than the old one, and in some cases, the savings were dramatic. They found that total average energy use per washer load dropped from over 7,000 Btu with vertical-axis (v-axis) washers to less than 4,000 Btu with h-axis washers. On average, the h-axis washer used 62% as much water as the v-axis machine. The original washers in Bern included machines in all conditions, from fairly new and relatively efficient to very old and probably less efficient. Indeed, the prereplacement energy and water consumption information showed wide variability in energy and water consumption among the population of washers in Bern. Some of this variability is due to the machine, while the rest is due to user settings and practices.

Superwash Saturdays
In order to evaluate how a large-scale changeover to horizontal-axis washers affects water utilities, the scientists coordinated two Superwash Saturdays. Participants were encouraged to postpone most of their week's washing until that day. The first Superwash Saturday was conducted on June 28, when the original washers were still in place, and the second on September 13, with the h-axis washers up and running. During the first Superwash, washers consumed about 20,000 gallons of water. During the second, an equal number of h-axis washers used only 13,000 gallons--a 36% reduction.

The average h-axis washer saved 10 kWh of energy and 130 gallons of water per week, compared to the average v-axis unit. Most of the energy savings were from reduced water heating. Assuming electric water heating (there is very little gas in rural Bern), at an energy price of 8.3¢/kWh and water heater efficiency of 85%, this would mean savings of $55 per year. Given that the water rate in Bern is around $2.50 to $2.75/1000 gallons, annual water cost savings would be about $16. The cost of the h-axis washer is just over $1,000 and the cost of a v-axis washer is around $400 to $600. Therefore, the extra cost of the h-axis machine over the v-axis one would yield a return on investment (without taking into account water and energy cost inflation) of about 12%-18%. In locations where water or energy rates are much higher, the return could approach 50%. (Other h-axis machines, such as the Frigidaire model, were not included in this study but have much lower suggested retail prices. In fact, under the Energy Star volume purchase program, the price of the Gibson h-axis washer, in lots of 42 or more units, is $517. If less expensive machines had comparable performance, they would have higher returns on investment.)

The study showed that the changeover to the h-axis machine had little impact on resident habits. There was no change in how much detergent they used, how they dried clothes, and whether they used additives. There was a 5% increase in average load weight for loads washed in the h-axis machine, probably due to the change from summer to fall.